| otherside |
Hey guys,
So far i've been amazed with the knowledge in here!.
I was reading the BAP200 document from national and seems like a very interesting design for the ones tha don't actually know what will be the final impedance of the speakers.
A couple of questions though
1.Has anyone built that design? If so, how good is the performance?
2.Is the servos good or bad? improvement in audio quality & improvement in safety and dissipation issues or degradetion of audio quality however improvement in safety and dissipation?
3. On this document (last pages) the rails are displied as +-42 volts which is the max of the IC? Can this be right ? Recommended from the manufacturer? I really don't get it.
Based on my calcs for a mid design for 6ohms speakers max rail is 30V.
4. Will this (exact) design work well on the LM4780? I'm asking since i the 4780 has better SNR and i have already 10 of them :-).
Has anyone built this with 4780s?
Thanks a lot. |
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| jaudio |
| quote: | Originally posted by otherside
Hey guys,
1.Has anyone built that design? If so, how good is the performance? |
Ive built it,it sound good
| quote: | Originally posted by otherside
Hey guys
2.Is the servos good or bad? improvement in audio quality & improvement in safety and dissipation issues or degradetion of audio quality however improvement in safety and dissipation? |
I did not use servos. I used the inverted mode and zeroed out the dc offset with a potentiometer on the + signal input
| quote: | Originally posted by otherside
Hey guys
3. On this document (last pages) the rails are displied as +-42 volts which is the max of the IC? Can this be right ? Recommended from the manufacturer? I really don't get it.
Based on my calcs for a mid design for 6ohms speakers max rail is 30V. |
That is the unloaded voltage, with the chips connected the voltage will drop a few volts.
| quote: | Originally posted by otherside
Hey guys
4. Will this (exact) design work well on the LM4780? I'm asking since i the 4780 has better SNR and i have already 10 of them :-).
Has anyone built this with 4780s
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It should work.
I never tried it but I think someone on this forum did. Search this forum there is plenty on the bridged parallel lm3886(4780) |
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| otherside |
jaudio thanks for the reply,
anyone else who used the servo circuit, or the LM4780? |
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| tiltedhalo |
| Servo's can poorly impact the sonic signature of the chips. There are many better ways to eliminate DC. |
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| otherside |
| quote: | | Servo's can poorly impact the sonic signature of the chips. There are many better ways to eliminate DC. |
For example? |
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| jimbo1968 |
Using the drv134 ?
I'm looking into this also, I want to build 2 BPa200 monoblocks. I've got 4x brianGT 4780 kits already. |
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| otherside |
After some research and after reading about 100 pages in this forum i think that the DRV134 is the way to go...
Already ordered some ;-) |
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| troystg |
digi01 (Zang) made and sold a few BPA 200 boards. I have yet to assemble mine but the layout and PCB's were outstanding.
He is VERY good with sharing. He "MAY" just give you the files to have some made. Would save you lots of time and they were debugged for you. |
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| gxlz |
| Someone on the forums had build ,sound is very good.I will build it useing 6Xlm3886 on each channel. |
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| veteran |
| I'm thinking about such amplifier but using 6xLM3875 chips. It's a simple way to make good sounding and powerful amplifier with all protection circuits. |
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